EPA Proposes New Ground Level Ozone Standards

June 28, 2007 // Published as a news service by IHS

The EPA said the proposal is based on the most recent scientific evidence about the health effects of ozone - the primary component of smog.

The proposal recommends an ozone standard within a range of 0.070 to 0.075 parts per million (ppm).

The EPA is also taking comments on alternative standards within a range from 0.060 ppm up to the level of the current 8-hour ozone standard, which is 0.08 ppm.

The U.S. made "significant progress" reducing ground-level ozone in the past quarter century, claims the EPA. Since 1980, ozone levels dropped 21% nationwide as the EPA, states and local governments worked together to improve the nation's air.

The proposed standards are being challenged by the American Thoracic Society.

Dr. David H. Ingbar M.D., president of the American Thoracic Society, called the proposed standards issued by the EPA for ozone pollution "unhealthy for America's kids, unhealthy for America's seniors and unhealthy for America."

"The science is clear," Ingbar said. "Ozone pollution is causing unnecessary, illnesses and death in America. The proposed EPA standards fall short of providing the protection needed to keep Americans safe from ozone air pollution."

By failing to adopt a more stringent ozone standard, the EPA is ignoring the strong scientific evidence that shows real harm being caused by ozone pollution at the current standard, said Ingbar.

To assist the EPA in analyzing and interpreting the scientific data, the EPA convened a panel of experts called the Clean Air Scientific Advisory Committee (CASAC).

CASAC, which included members with academic and industry backgrounds, analyzed the available data. They unanimously concluded the current standard does not protect public health and recommended a standard between 0.060 and 0.070 ppm/-8-hours, according to the American Thoracic Society.

Ground-level ozone is not emitted directly into the air, but is created through a reaction of nitrogen oxides and volatile organic compound emissions in the presence of sunlight. Emissions from industrial facilities, electric utilities, motor vehicle exhaust, gasoline vapors and chemical solvents are the major man-made sources of these ozone precursors.

Ozone can harm people's lungs. Ozone exposure can aggravate asthma, resulting in increased medication use and emergency room visits and it can increase susceptibility to respiratory infections.

The EPA is also proposing to revise the "secondary" standard for ozone to improve protection for plants, trees and crops during the growing season.

The secondary standard is based on scientific evidence indicating that exposure to low levels of ozone can damage vegetation. The EPA is proposing two alternatives for this standard: a standard that would be identical to the "primary" standard to protect public health; and a cumulative standard aimed at protecting vegetation during the growing season.

The EPA said it is estimating the health benefits of meeting a range of alternative ozone standards based on published scientific studies and the opinion of outside experts. These findings will be detailed in a Regulatory Impact Analysis to be released in the next few weeks, which will include both the estimated costs and benefits.

The agency will take public comment for 90 days following publication of the proposal in the Federal Register and will hold four public hearings. The hearings will be held in Los Angeles and Philadelphia on Aug. 30 and in Chicago and Houston on Sept. 5.

Comments should be identified by Docket ID No. EPA-HQ-OAR-2005 -0172. They may be submitted to the federal eRulemaking portal at http://www.regulations.gov or via e-mail to a-and-r-docket@epa.gov).

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The EPA is expected to issue final standards by March 12, 2008.*

Source: U.S. Environmental Protection Agency (EPA).